CVE-2026-35091 Corosync: corosync: denial of service and information disclosure via crafted udp packet
Remote attackers can cause denial of service and disclose memory contents in Corosync by sending crafted UDP packets, affecting Linux distributions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-35091?
CVE-2026-35091 is a high-severity denial of service vulnerability in Redhat Enterprise Linux, published on 1 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A flaw was found in Corosync. A remote unauthenticated attacker can exploit a wrong return value vulnerability in the Corosync membership commit token sanity check by sending a specially crafted User Datagram Protocol (UDP) packet. This can lead to an out-of-bounds read, causing a denial of service (DoS) and potentially disclosing limited memory contents
Weakness: CWE-253
Which versions are affected by CVE-2026-35091?
It affects 3 products.
Linux distribution packages (1)
corosync openSUSE:Tumbleweed | All versions | 3.1.10-4.1 |
Products include Corosync Corosync, Redhat Enterprise Linux, Redhat Openshift.
How do I fix CVE-2026-35091?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-35091 being exploited?
There is no known exploitation of CVE-2026-35091 in the wild and no public exploit code.
Other vulnerabilities in Redhat Enterprise Linux
Sources
Also known as AZL-81981, DEBIAN-CVE-2026-35091, GHSA-hmg2-5h4j-37m9, UBUNTU-CVE-2026-35091, openSUSE-SU-2026:10488-1.